Electric switch



iatented Au 9, 1927. I

UNITED. STATES :PATENT' oFFIca. r

WARREN R. WALKER, F BLOOMFIELD, NEW JERSEY, ASSIGNOR TO COOPER HEWITT ELECTRIC COMPANY, OF HOBOKEN, NEW JERSEY, A CORPORATION OF NEW JERSEY.

I ELECTRIC swrroH. f

Applicationnled February 15, 1926. Serial n. 88,392.

The present invention relates to electric switches of the liquid flow type and particularly to mercury switches. The invention further relates to switches of this type havinga sealed envelope into which are sealed electrodes between which current path is made and broken by the movement of the mercury-with relation to the other parts of the switch, and in which a wall or septum which has a passageway therethrough is positioned across the envelope preferably between the electrodes therein'and which is utilized for separating mercuryin the switch into more than one part in'the open circuit position thereof and which ermitsjoining of the said parts of mercury t rough the passageway thereof in the closed posltion of the switch, said septum being of specialarc resisting material and preferably having the wall of the. switch fused thereto.. The inven.- tion further relates to a switch of this type having an'envelope of comparatively cheap glass fused or laid down on; to a septum which is separate therefrom and which is made of a material highlyresistant to electric arcing. 3

Switches of this type are adapted for making and breaking circuit therethrough, either by rotation of the switch about an axis extending" substantially normally through the septum, or by tilting of theswitch in a plane of that axis.

Variousother objects and advantages of the invention will be obvious from the following particular description of embo d1 ments of my invention or froman inspect on of .the accompanying drawing; and the 1nvention also consists in'certain new and novel features of construction and combinations of parts hereinafter set forth and clalmed.

In the following description andlin the claims parts will be identified by specific names for convenience of expression, but they are intended to be as generic in their application t permit. I v

In'the accompanying drawing are shown for purposes of illustration one form of mechanism with certain modifications thereof embodying the invention, in which i Fig. 1 1s a longitudinal sectional view of" anemb'odime t of the-switch of my inven-- similar parts as the art will device of Fig. 1 taken along the line 22 andlooking in the direction of the, arrows in that figure,

' 3 is a longitudinal sectional View of an alternative embodiment of my invention showing electrode extensions which extend around the interior of the envelope, and showing the switch in the open circuit posiion,

F ig. 4 is a sectional view of the deviceof Fig. 3 taken along line 4-4 and looking in the direction of the. arrows, but with the switch in the'closed circuit position, Fig. 5 is a face view of an alternative form of septum having two "perforations therethrough diametrically spaced,

Fig. 6 shows an alternative embodiment of the septum having one perforation which is extended arcuately for permitting the closing of the circuit durin the predetermined period of time while t e. switch is r0'- tating on its axis at a predetermined rate of speed and likewisebe made to have the circuitopen jtl1erethrou h for a corresponding predetermined perio of'time;

Fig. 7 shows a' septum having a simple tum is embodied circuit may be established alternately for vdifi'erent periods of time .when such rotation is made at a given-rate of speed, Fig. 8 shows a septum having two arcuate openings diametrically spaced vwhereby a similar result is produced as with the septum of. Fig. 6 but inwhich the .open circuit periods are shorter 'with respect to the closed circuit periods;

' y In Figs. land 2 ofthe drawing the envelope 1 preferably of boro-silicate glass such as G702P glass carries-sealed therethroughon each end electrode leads 2 and 3 which extend inwardly toward each other .90 perforation therethrough at oneyposition and and are axially aligned. Each of the leads 2 and 3 carries an electrode 5 connected thereto which extends toward the envelope wall which contact with the body of mersides between the walls of the envelope 1 and is held in place by having the wall of the envelope fused down thereonto about edges thereof. Between its point of support and its edge said septum 7 has formed therethrough a perforation 8 for the flow of mercury toconnect in the closed circuit position of the switch two pools into which the mercuryis formed on either side of the septum 7; a

In the operation of this embodiment of my invent-ion the switch .is rotated on its axis to bring said perforation 8 below or above the level of the mercury 6 for making and breaking of a current path therethrough. In its operation as a simple switch it can be rotated backward and forward to a small part to bring said opening 8 below or above the surface of the mercury as .desired. In operating the device as a time switch it is rotated continuously at a predetermined rate of speed whereby the septum in travelling from its point of emerging from the mercury to its points of immersion therein occupies the predetermined; period of time and likewise the movement of the opening from this point of immersion into its point of emergin from the mercury occupiesthe correspon ing period of time, the time periods of themaking and breakin of the circuit being recorded by the spee of rotation of the device. For obtaining the making of a circuit through the device at shorter intervals than that possible with the device of Fig. -1 with res ect to the timeperiods of the openin of t ecircuit aseptum such as shown in 1g. 5 is used where a plurality of perforations 99 are 'formed.

These ma .be either diametrically spaced or otherwise equally spaced or theymay be spaced atunequal angular distances a out the center of the septumand center of rota- .tion whereby different periods of make and break may be obtained as desired. In Fig. 6,

for example, is shown the single perforation formed in the shape of an arc whereby at a given rate o-f speed of rotation the period of cicrycuit inake is lengthened and the ration 9 at one point and a ate eriod of rcuit break is shortened. In Fig. is shown a septum having a' small perforforation 10kat another portion whereby s obtained through the rotation of the switch'intermittent periods of circuit make which are unequallin duration. And in Fig. 8Iis' showntwo equally spaced arcuate perforations 10 in the septum-Z,

arger and arcu- I -flow type, a sealed envelo The device of-Figs. 1 and 3 may also be" operated by tilting in which operation the perforation 8 isleft in its position shown, 7

that electrodes 5', 5 mounted on electrode switch simileads 2 and 3 extended circumferentially around the interior of the envelope .and at' short distance therefrom whereby during the rotation of the switch for makin and breaking circuit therethrough a section of each of the electrodes is at all times'immersed in' mercury 6.and any possible arcing between these electrodes in the mercury is precluded.

The envelope of this. switch is preferably made of a glass, for example, a boro-silicate glass, the glasses generally known in the trade as Pyrex glass and G702P glass being particularly suitable for this purpose. For

the septum a ceramic material is used which has a thermal co-eflicient of linear expanslon substantially the same as that of the glass.

Materials which have co-efiicientsof expansion at or near those of G702P glass for-example, are porcelains known in the trade as Fireite, which has a co-efiicient =of expansion of 000000354, Coors porcelain with a" co-eficient of expansion of 0.0000034, and

Elemite porcelain which has the same coelficient of expansion as G702P glass.

As in other'switches, an atmos here of hydrogenv or other gas is include in the switch envelope to serve to quench arcs formed during operation of the switch' and to' conduct heat'flfrom theinterior-to the .walls thereoh- I claim:

1. In an electric switch of the mercury flow type, asealed envelope of glass,:elec-. trodes sealed into the envelope, mercury in the envelope, and a septum of arc resisting material ositioned across the envelope in the line 0 flow of mercury therein for opening and closing a circuit therethrough,.the

wall of; said envelope bein fii'sed down against said septum-"and sai septum being formedwith a passagewa for the mercury.

2. In an electric switc fi w type, a sealed envelope of glass, electrodes sealed into the envelope, mercury in the envelope, and a septum of ceramic maof the mercury terial fpositioned across the envelope in the line 0 flow of mercury therein for openin and closinga circuit therethrough, the wal of said envelopew being fused downagainst said septum, and said septum being formed 1 ectric swltch of themercury with a passagleway for the mercury.

3. In an 'e I of glass, elep-- trodes sealed mto the enve ope, mercury m Y the envelope,

and a septum of arc resisting material having a thermal co-eflicient of expansion substantially that of said glass positioned across the envelope in the line of flow of mercury therein for opening and closing a circuit therethrough, the wall of said envelope being fused down against said septum, and said septum being formed with av passageway for the mercury. a

4. In an electric switch of the mercury a sealed envelope of glass, electrodes sealed into the envelope, mercury in the envelope, and a septum of ceramic material having a thermal co-efiicient of expansion substantially that of said glass posi-. tionedacross the envelope in the line of flow of mercury therein for openin and closing a circuit therethrough, the wal of said envelope being fused down against said septum, and said septum being formed with a passageway for the mercury.

5. In an electric switch of the mercury flow type, a sealed envelope of glass, electrodes sealed into the envelope, mercury in the envelope, and a septum of porcelain-having a thermal co-efiicient of expansion sub stantially that of said glass positioned across the'envelope in the line of flow of mercur therein for opening ,andclosing a circuit septum being therethrou h, the wall of said envelope bemg fused own against said septum and'said septum being formed with a passageway for the mercury.

6. In an electric switch of the mercury a sealed envelope of boro-silicate glass, electrodes sealed into the envelope, mercury in the envelo and a septum of ceramic material positioned across the envelope in the line of flow of mercu therein for opening and closing a circuit therethrough, the fused down against said septum, and'said rmed with a passageway for the mercury.

7. In an electric switch of-the mercury flow type, a sealed envelope of boro-silicate glass, electrodes sealed into the envelope, mercury in the envelope, and a septum of porcelain positioned across the envelope in the line of flow of mercury therein for opening and closing a circuit therethrough, the wail of said envelope being 'fused down against said septuih and said se tum being formed with a assageway for t e mercury. Signed at Ho oken, in the county of Hudson and State of New- February A. D. 1926,

WARREN R. WALKER.

40. wall of said envelope being Jersey, this 9th day of 

